This invention relates to a process for providing a surface with a fire-proof and/or wear resistant lining, further referred to in this application as lining. In engineering it is common practice to apply a lining of a fireproof and/or wear-resistant material to a surface which is subjected to high temperatures and/or mechanical and/or chemical loads, such as the surfaces of vessels, vessel internals or pipe-work connecting vessels used in, for example, the cracking of petroleum products.
One of the major drawbacks of the processes for applying such a lining to a surface that are presently used, is the commercially unattractive installation time. For example, the installation time for a fire-proof and/or wear resistant lining consisting of a hex mesh or floor steel anchoring system in combination with a phosphate bonded ramming mass can amount up to 75 hours/m2. In addition the linings of this type can be sensitive to thermal shocks and are difficult to repair. Furthermore it is difficult to maintain a uniform quality.
Commercially more attractive shorter installation times can be obtained by using a lining comprising a single point anchoring system, such as for example the system described in U.S. Pat. No. 5,353,503. A problem of these rather large anchors is that due to the difference in thermal expansion of the anchors and the lining, tensions can occur between the anchors and the lining, resulting in cracks in the lining. The cracking can even occur at the relatively moderate temperatures applied during drying of the lining. This problem is especially encountered when so-called wholly or partly cement-bonded materials with a low abrasion resistance are used as a lining material.
In his article titled xe2x80x9cEquation helps select refractory anchor systemxe2x80x9d, published in Oil andGas Journal, Aug. 30, 1982, pages 122-125, M. S. Crowley describes the use of mastic tape, wax and plastic coatings to cover the ends of independent anchors before the lining material is applied. According to this article, in service, i.e. during operation, the coating burns out and leaves a small void space around the anchor so it can expand thermally without stressing the lining. This article is, however, silent about cracking problems which occur due to the build up of stress during drying of a lining.
Because the described anchoring means are welded onto the surface, coating can only be applied after this welding step in order to avoid any damage to the coating. This adds another step to the installation process, making it more complicated and more laborious, resulting in increased installation time.
It would be useful to provide a less laborious process for providing a surface with a fire-proof and/or wear resistant lining, resulting in a commercially attractive installation time, while preventing the lining from cracking during drying of the lining.
This is achieved by a process to provide a surface with a fire-proof and/or wear resistant lining comprising the following steps:
a) mechanically fixing anchoring means to the surface, which anchoring means are pre-coated with a coating that melts at a temperature in the range from 40 to 100xc2x0 C.;
b) applying a lining material onto the surface provided with the anchoring means;
c) curing the lining material to obtain a solid mass;
d) drying the lining, to a temperature at least sufficient to melt the coating on the anchoring means, to obtain a fire-proof and/or wear resistant lining.